Apparatus for pickling metal articles



4, 1921,: 4. SHEETS-SHEET 1.

mm, uwwkm. sul

`,wPLxcATloN FILED o cT. 1`2. 1920.

HQSi MARSH AND n. s. COCHRAN.

APPARATUS FR PICKLING METAL ARTICLES.

W/TNESSES H. S. MAHSH AND R. S. COCHRAN.

APPARATUS roR Plcmme METAL ARncLEs.

APPLICATION FILED OCT-12, 1.920. y I 1,392,781., `lPatented 0015.4, 1921.

4 SHEETS-SHEET 2.

H. S. IVIARSH AND R. S. COCHRAN. APPARATUS FOR 4PICKLING METAL ARTICLES.

APPLICATION FILED OCI. I2, 1920.

' H. s. MARSH AND H. s. COCHRAN.

APPARATUS FOR PICKLING METAL ARTICLES.

APPLICATION FILED ocT. 12, 1920.

1,392,781.. Patented Oct. 4, 1921.

4 SHEETS-SHEET 4.

Flam.

FIEXIII.

r EENRY'S. MARSH AND RALF S. GOCHRAN, 0F YOUNGSTOWN, OHIO.

APPARATUS ron noname armar.. metas.

wearer.

Specification of Letters Patent.

Patented Qct. el, 1921.

Original application tiled Mai-c1127, 1920,'-Serial No. 365,173. Divided and this application tiled @atelier To all 'whom 'it may concern:

12, 1920. Serial No. 416,547.

Referring to the drawings, Figure I is Be it known that we, HENRY S.- MARSH adiagrammatic View of the entire system of and RALF S. COCHRAN, residing at Youngs-I. apparatus' 1n which and in the operation town, in the county of Mahonin and State of Ohio, both citizens of the United States, have invented or discovered certam new and -usefu`l Im rovements in Apparatus for Pickling etal Articles, of which improvements the followlng is a specification.

This is a division of application Serial No. 369,173, led March 27,1920. In that application a method of pickling metallic articles is claimed and with the method an of which ourY present invention is realized. The succeeding figures of drawing show to larger scale, and in the sequence of the progress of the material under treatment, the several component pieces of apparatus. Fig. II isa diagrammatic view in side elevation of the scale breaker, -in which thev sheetsteel is repared for the pickling operation; Fig. II is a View in transverse vertical section on the une r11-rfi, rig. through the transfer table and adjacent conveyer; Fig. IV is a View in side elevation of this same transfer table in its relation to the conveyer; Fig. V

is a view in transverse vertical section, on the plane indicated by the line V-V, Fig. I, of the pickling chamber and of the conveyer as related thereto; Fig. VI is a planl view, to smaller scale than Fig. V, of

ling metallic articles generally, whatever.

be the shape or substance. The invention cons1sts 1n improvements V1n apparatus for Y conducting of pickling in continuous operation. The idea of pickling in/ontinuous operation has been proposed before, but never to our knowledge has it been successfully pickling chamber land Yrinse chamber; Fig. VII is a view in longitudinal vertical section, and to equal scale with Fig. VI,

carried out. Indeed, as heretofore proposed,

a highly concentrated acid has been nieces-` sary, and for this reasonvalone those pro-A posals have been impracticable.

-The operation of our present invention may be successfully conducted in cordina- A tion .withy that of the continuouscirculation Y of plckling solution, after the manner-dis- Letters Patent, file closed in our now r1pending application for January 9, 1920, Serial No. 350,383. It need not, of course, be coordinated with this or any other particular' system for vmaintaining the eiiiciency of the pickling solution, but, since we have so developed it, we shall here describe it in that coordination.` Incidental to the apparatus which forms the subject matter of 4this ap-` plication are means for loading the material to be treated upon the conveyer and means for removing the material when treated from the conveyer.A These means form no part of the present .invention but are made thesubject ofanother application for United States Letters Patent filed by us August 16, 1921, serial N0..492,e65.

through pickling chamber and rinse chamber, the plane of section being indicated by the une vII v1I, Fig. v1; Fig. vm

is a 'view in transverse vertical section, and to fa scale somewhat larger still than that of Fig. V, through the drier, the lane-of section bein Fig. I; Fig. X is ia view in side elevation of the drier; Fig. X is a view in' transverse vertical section through the discharge, the

.scale being somewhat less than that of Fig V, and the plane of section will be found indicated at X-XhFig. I. Fig. XI is a view in side elevation of the discharge.

Fig. XII shows in two `fragmentary sectional views ari expedient for adapting the conveyer for the reception of smaller sheets than the maximum. Figs. XIII and XIV areV views in transverse section and in side elevation of the pickling chamber, adapted to the incidental possibility of collecting the hydrogen gas generated' in the pickling operation. l Figs. XV and XVI are views 1n transverse section through the pickling chamber, showing how certain of the machine partsof Fig. V may be duplicated,

with advantages` which w1ll be explained in the sequel.

lane indicated by the The'vnecessity forpic'kling steelsheets. ,I

the course v or fabrication is universally known, and need not be dwelt on.

Beginning with the scale-covered sheet, and beforesu'bjecting it to the pickling operation, we, in the practice of our invention, referably put it through a scale breaker. e may use as a scale breaker a machlne of the sort commonly used for straightening sheets and plates, and such a machine'will be used in the regular way,-though ordinarily the degree of bending to which the sheets are subgected will, to satisfy our purposes, be greater than that ordinarily required when the machine is used for straightening. It the sheets to be dealt with areheavy, a specially designed machine may be .re uired, to withstand the lstrain.

he scale breaker is indicated at l, in Fig.

I of the drawings, and in Fig. II an ordinary sheet-straightening -inachine is diarammatically shown, with a sheet advancing through it and under oingthe scalebreaking process. The mac ine consists essentially of a succession of positively driven .rolls 11 (the number is not material) beway and lthen the other will loosen the scale,

so that much of it will drop off, and what remains will be to such extent loosened that in the ensuing pickling operation the acid will the more readily work underneath and ,gain access to the steel. rl`hese rolls of the scale breaker may\be, and'preferably are,

heated (as by a flame applied beneath), to

heat the sheets and so prepare them for the ensuing pickling operation.

rThe sheets may be fed to the scale breaker one b one, by hand. In Figs. I and II, and

elsew ere throughout the drawings, the ar-y rows marked a indicate the direction of the advancing sheets.

. vFrom the scale breaker-the sheets are delivered one by one to a table 3, Fig. I, more fully illustratedin Figs. III and IV. The

table 3 is's'o arranged that the sheet (A) delivered by the scale breaker will initially rest upon it, in the full-line position indicated in Fig. III, in which the center of gravityof. the sheet lies beyond the edge of .the horizontal portion ,of the table. The sheet will advance upon table 3, maintaining this position, lintil its rear edge passes from the rolls 13`of the breaker. Thereupon it will swing of itsow weight 'from the fullline position .shown 1n Fig. III to the dottedmeager line position, and will slip down the apron 31 with which table 3 isprovided and come to positionin conveyer 4.

The conve er 4 will be understood best by comparing tllie showing of Fig. I with that of rig. v.

body member, in the form of a belt or chain,

equipped with rollers 41 which travel in It consists of an endless iiexible guide channels 42. It is so disposed that,

throughout its work-performing reach, it extends through thev succession of chambers presently to be described, and carries the sheets with which it then is laden Vthrough these chambers one after another; whale,-`

throughout its idle return reach, it ris out of the way. Conveniently, and as shown, the

idle, return reach of the conveyer is above the Work-performing reach, and the workcarrying parts there assume inverted position.

The conveyer 4 is provided Withlaterally extending arms 43, and from these arms nger's 44 extend.` rlihroughout the worklperforming reachif the conveyer, these iingers stand' vertically. rthey are arranged in pairs, and their tips mayiiare divergently,

to insure the automatic reception of the'.

sheets descending from table 3. The sheets come to rest in the notch defined by the successive pairs of fingers; the fingers engage the sheets at intervals on opposite sides,

and support them in edgewise standing position' as they are borne forward through the chambers. All this is clearly' shown in the drawings. Throughout thatv portion of its path where it receives the sheets, the conveyer may rest upon a springbacked buffer plate 45.

Those parts of the conveyer. which in the course of operation are exposed to acid,

preferably made of metal, may be made of such acid-resisting'material as Monel metal or Duriron (a cast iron high in silicon).

The pickling chamber is indicated at 5, Fig. I, and its particular constructionwill be understood oncomparing Figs. V, VI, and VII. It is a long narrow chamber, sursounding'the conveyer throughout a portion of its work-performing reach. The wallsv of the picklingchamber are preferably heatinsulating, and may'fconveniently be lformed of wood. Within the'chamber, and on either side of the path of the advancing sheets, is

arranged a succession of^ s ray nozzles,`

whichiconveniently take the orm of`vertically extending perforated pi es 51, hung at suitable successive intervals rom mains or headers 52 above. The lower ortion of the chamber constitutes a troug wherein a body of acid B may accumulate. From this trough circulation pipes 53 f communicate with the headers 52. Pumps 54 are provided. 1

to maintain circulation'.

Atv intervalsy throughout the lengthl of 'i chamber v5 the trough is dammed across by ist meager barriers 55. Y (Two such are shown in Fig. VI). And Ait will be observed that these barriers subdivide the pickling chamber into distinct units, so far as concerns acid circulation, there being a separate circulatioln lthough itmay be continuous throughout the length of the pickling chamber, preferably is not so, but consists rather of a succession of disconnected boards overhanging, each, one of the outlet openings from the trough through the circulation pipes 53. The solution dripping from the material under treatmentl would, but for this shelf, keep the body of solution -B agitated and particles of scale in suspension, and these, carried through the circulation pipes, would tend to obstruct the spray nozzles. The shelf by its presence prevents agitation, thus allowing the particles of scale tov settle, and insures a circulay ltion of clearer solution through the pipes 53 and the spray nozzles. The shelf is preferably discontinuous, to the end that the' accumulated sediment of scale may more readily be removed from the bottom of the trough. Such removal will occur at proper and convenient intervals.

insure a more thorough mingling of the relatively 1 enfeebled acid runing from the sheets undertreatment with the relatively.

'vigorous body of pickling solution B, to

free end. It will of course be suitably sup-Y ported; in this respect the showing of Fig.

is diagrammatic.

To prevent a splashing out of the spray of pickling solution, the wall of the` pickling chamber may, where it is slotted to' allow the entrance) of arms 43of the conveyer, conveniently be constructed asVV shown in Fig. V. The-wall below stands farther out--the chamber is wider below than above;

and the arm 43 of the conveyer may at the point of passage ofthe slot be stepped downward as shown, to the end that the vertical The functions of the shelf, already indicated in part, are, in addition, to

spacing of the margins `.of the slot may be dlminished.

Acid is introduced to the trough in the bottom of the pickling chamber through a supply-pipe 56, arranged preferably at one end of the chamber 5, and advantageously at the remote or delivery end-to the end from which the sheets advance to the next stage of operation. The next chamber (which will presently be more fully described)- is the rinse chamber. This rinse chamber is structurally a continuation of the pikling' chamber 5, and' from a similar trough in its bottom rinse water flows over a barrier 57, similar to the barriers 55 already described, into the trough in chamber 5. Through an exhaust pipe 58 at the oppositefend (the receiving end) of' the pickling chamber, thepickling solution is led away.

When the trough in the bottom of the chamber 5 is full of pickling solution, pickling may be effected upon sheets advancing through the chamber, by driving pumps 54,

/and so causing, the solution to be sprayed y mini'shing strength and carries an increasing iron content, from inlet to'outlet. Preferably (though not necessarily)y the arrangement is that shown: the entering sheets are first sprayed upon by the solution at its weakest, and as they advance through the pickling chamber they receive solution of increasing Strengtln'until at the end they are sprayed upon 'by fresh solution. tain economies of this 'preferred arrangement, in which solution and sheets under treatment advance in opposite directions, are obvious. There is this further, less obvious economy: the concentration of the copperas in solution toward one end of the pickling chamber leaves the pickling solution less contaminated elsewhere. The efficiency of the body of solution as a whole is thereby increased, and ,less refrigeration is subsequently necessary for the removal of the copperas 'and the reclaiming of the acid solution. V

The acid supplied through pipe 56 is, as will presently be explained, preferably the reclaimed acid flowing from: our improved reclaiming apparatus, to which reclaiming apparatus the `spent acid flowing out at exit 58 is fed. This reclaimed acid is concen- Cer# trated to a' degree greaterthan the pickling operation requires. Hence the ladvantage of diluting it with rinse water from the rinse chamber. If with such an arrangement the heated in the scale breaker; the walls of the,y

pickling chamber are heat-insulating. The effect is that pickling is done at elevated temperature, and withconsequent gain 1n time.

, If, in addition to the measures enumerated,

land will be understood on still greater accessions of heat are required,

heaters 59 may beprovided for the circulation pipes 53.

The rinse chamber 6 is, as has been said,

'continuous structurally with pickling chamber 5. The interior arrangementl is essentially the same as in the pickling chamber, comparing Figs. V, V I, a-nd\ VII. Circulation pipes 63 are shown in Figs. VI, and VII, in which pumps 64 are arranged. Through. pipes 63 water passes to headers 62, whence it is sprayed 'through spray pipes 61. A, lwaterinlet is indicated at 66. In the rinse chamber a circulation of hot water is maintained, rather than of pickling solution. .Under the spray of hot water in the rinse chamber the advancing sheets are washed free of acid, and

from the rinse chamber the acidulated rinse water continually and gradually overflows into the pickling chamber. The rinse water will conveniently be condensed steam, not far below the boiling oint.

'.Next in succession a ter the rinse chamber stands `the drier, shown diagrammaticaflly in Fig. 1, in its place in the organization, and

shown in its essential features of yconstruction in Figs. VIIIl and IX. The drier is simply a. chamber through which the now pickled and washed sheets pass, and in 'which conditions of temperature and circulation are suchas to evaporate from the sur-faces ofthe Sheets the water with which the surfaces are wet. As shown in an exemplaryway in Figs. VIII and IX, this chamber is long and narrow. conforming in some' degree in its shape tothe pickling and rinse chambers; means of heating are indicated, consisting in this case of a bed of coals on a grate 71; a chimney 72,establishes draft to nourish the fire and to carry away the watervapor as it forms. The slot in the side wall to admit the arms 43of the conveyer is arranged essentially .as in the pick-` ling and rinse chambers, but 1t`will be noted that, inasmuch as within chamber 7 there is' no spraying of liquid, the reason does. not

wearer.

here exist for the widening ofthe chamber below and introducing the conveyor arm in a 1 stepped formation downward; accordingly,

the slot cuts through an otherwise vertical wall disposedin a single substantial plane.

The advancing conyeyer carries the sheets one by one through pickling chamber, rinse chamber, and drier in turn, and then to the discharge mechanismS (Fig. I), where the sheets, now pickled and ready for further treatment, are removed from the conveyer.

This discharge mechanism may take any form desired. We have (in exemplary way, so far as concerns our broader claims) shown a magnetic discharge mechanism, and this we shall now describe, with particular reference to Figs. X and XI.

Adjacent the path of advance of the sheets borne in conveyer 4, beyond drier 7 and extending parallel with that path, is a pair of' magnetic rollers 81.. The particular construction of these rollers need not be dweltpn; such rollers are on the market; their characteristic features are that, attracting to their surfaces bodies formed of magnetic material, by turning they convey such bodies from one point to another. The position of rollers 8l relatively to the path of sheet advance is sufiiciently indicated in the drawings, and the direction of. rotation is indicated by arrow c. Conveniently two rollers are employed, jmounted on a common axle, and adjustable in their distance apart, to accommodate the mechanism to sheets of different size.

A guide 82 may be provided, to bring the advancing sheet to position adjacent the rollers. position to be acted on, it automatically trips aimake-and-break device 83, and edects energizing ofthe electro-magnets of rollers 81, which up to that time had not been en ergized.

As an advancing sheet comes to Immediately the rollers attract., thesheet, and, as they continue to turn, they los sheet advances relatively to the roller, so

that its forward edge projects farther and farther from the roller. This forward edge passes into fa suitable guideway, conveniently formed by opposite lines of idle rollers 84. The momentum of the sheet carries itforward (and its advance may be aided by gravity) the limitations imposed by the guideway cause the sheet to break Contact with rollers. 81, and the delivery is made to any suitable receptacle. F ig. X shows a crate 85 'in which has been stacked a succession of sheets coming through the discharge mechanism. At a point` in fits course Where the magnetism of rollers 81 is no longer advantageous or desirable, the

iso

the magnets of rollers `81. This leaves the rollers in condition, permitting the next advancing sheet to come to position opposite the discharge mechanism, and'then a new shifting of trip 83 (which meanwhile has come to initial position-either in consequence of the swinging of trip 86 or otherwise) begins .the operation anew. It will be understood that after each operation trip 86 resumes again its initial position, either in consequence of the shifting of trip 83 or otherwise.

Referring now to Fig. I, it will be observed that the conveyer, iii traversing, in the direction indicated by the arrow w, so much of its path as is in dotted lines there indicated, is loaded with a succession of sheets, and that it carries these sheets through pickling chamber, rinse chamber,

and drier, and finally in the discharging mechanism is relieved of its burden. lieved, the conveyer' returns upon itself, it being, as was initially explained, in form an endless belt lor chain. The disposition of the return reach of the conveyer is suiliciently indicated in Fig. V.

Figs. XII-XVI illustrate various supple'- mentary or variant features of structure, and may be briefly described.

In Fig. XII is shown in detail how. a block 46 may be inserted between'each pair of fingers 44 ofA the conveyer, to diminish the'depth of the slot defined thereby, and to adapt the conveyor temporarily to sheets of smaller size 'than those primarily intended. These blocks will be secured b ins 47, passing through them and through ngers 44, to lprevent falling out when the conveyer on itsreturn reach is inverted.

Figs. XIII and XIV illustrate an adaptation of the pickling chamber for the recovy further description is necessary.

cally indicated at 91,

ery of the hydrogen Tgas generated in the pickling operation. he slot in the chamer wall through which the .arm 43 of the conveyer extends is sealed by the liquid accumulating in the trough in the bottom of the chamber, the particular construction of wall and slot and conveyer arm are clearly` indicated in Fig. XIII, and the essential features will be taken in at a glance.

When hydrogen is to be recovered, the ends of the pickling chamber will be closed, and the roof of the chamber will rise to a chimney 90 through which the hydrogen ma be ledoi to suitable apparatus for col ecting, drying, and compressing the'hys drogen. Such apparatus, is diagrammatifFig. I. vAs has just been'said, the ends o `pickling chamber will in this case be closed, partially at least. 'I he end walls may conveniently .be

. made wholly or in part of sheet rubber, and

Y Y through the rubber slits may be cut,t o allow the passage -'et' tine conveyer. The bearing vof our invention for continuous pickling of the aps formed by the edges of the slits as is illustrated in Fig. XIV. And,\t^hat the opening through the end walls of the chamber shall in the course of operation be kept as 'small and as tightly sealed as possi' ble, the trough may be prolonged beyond the end walls of the chamber, and the submersion of the conveyer in the solution in the trough (and, at the other end, the emerging of thel conveyer) may be effected beyond the limits of the hydrogen-collecting chamber. This is indicated in Fi XIV. To allow the conveyer to pass the arriers which extend athwart the trough at intermediate points, the barriers themselves may be partially cut away. The barriers ma be formed, so far as necessary, of suc fiexible material as sheet rubber, through which openings for passage of the conveyer may be formed. By such provision, as will be understood, the sizeof the openin through the barriers, while sufficient, will still be ke t lat a minimum.

Fig. X indicates that a double liner of plates may be carried on the succession of conveyer arms 43, and that within the plekling chamber and the rinse chamber the spray apparatus may be correspondingly doubled. It will be understood that, with 105 this arrangement, two charging tables ,3' will be provided, one on either side of the con' veyer, and, corres ondingly, at .the point of discharge, dup icate discharging appafr ratus will be arranged on either side of the conveyer.

Fig. XVI indicates that the conveyer may be relieved of twisting strains by providin duplicate oppositely extending arms 43, an that the several parts of the apparatus shown diagrammatically in Fi I and now described may be correspon ingly duplicated, on either side of such a conveyer.

We remarked at the outset that apparatus might be combined with a system for cii# culating the picklin solution in continuhsg 'cfcle and relieving itat a .suitable point in e circuit of the accumulating copperas (the product of pickling) and incidentally replenishing the acid content. .Such a system is described in our pendin *application, iledJanuary 9, 1920, Seria No. 350,- 383. Indeed, in suclia combination itself lie specific features of invention. It re-fwo -but still carrying its burden o fcopperas, is

the pickling chamber again.

mains now to follow the course of the circulating pickling solution, and to indicate vto what treatment it is subjected, and 1n 'what apparatus.

We shall begin 'with the spent solution emerging from the picklin chamberV through orifice 58, Fig. VII. he solution as it here emerges is, for pickling purposes, relatively weak and ineffective. A large part of the sulfuric acid which the solution carried when it entered the pickling chamber has reacted with the iron 'of which the sheets are essentially composed, and been converted into copperas, and this copperas has continued in solution, enfeebling the solution by its formation, and` tending by its presence in solution to render the enfeebled acid still less effective than other.- wise it would be. The solution emerging then throu h orifice 58 is a relatively weak solution og sulfuric acid in water, carrying also in solution a substantial burden of copperas, A' v- From the pickling chamber `the solution ows, conveniently b gravity, to a settling tank 92 (Fig. l). 'llhis may be merelya large-wooden tank of sufficient size to hold all the liquid on hand at any one time. ln this tank whatever scale and other solid matter may be carried from the pickling 'chamber may settle and be removed. Here too will' be added such quantities of fresh acid (ordinarily of 60% purity-possibly as high as 66%) as are requisite to -bring the reclaimed acid to the proper strength for re-introduction in continuous operation to The reason for adding the acid at this point will presently be explained; herein is a feature of invention with us. An acid storage tank -93 is indicated, from which acid may flow to tank 92 in lsuch measured quantities and be A desired. roin tank 92 the acid,.now strengthened 'with such continuity or at such intervals as pumped by a pump 94 to reclaiming apparatus 95. This reclaiming apparatus need not here detain us; it is fullydescribed in our application alluded to. In it the cir- -culating stream-of solution is, by means of cooling and agitation, freed of the copperas. The .crystallized copperas, wet with acid solution, 1s carried to a centrifuge 96, where the acid solution is separated and returned to the line through which thereclaimed acid solution -is delivered from the peras 'crystals may,

reclaiming a paratus 'to ow to thev pickling he accumulated mass of copwhile still in the centrifuge, .be rinsed in water and then removed, 1n condition sufficiently free from i .acid and suliiciently dry to be marketable.

We here interrupt tle description to give, explanationt'of .a vreiinement in the reclaimigaeaaei ing operation lt has just been remarked that there is advantage 1n making the additions of fresh acid before the removal of the copperas.. We find that, by so increasing the acid strength of the solution still 70 carrying the copperas, the copperas may be removedmuch more rapidly and much more completely than otherwise.

From the reclaiming apparatus the acid passes, on its way back to the pickling chamber, throu h a heater 97, to restore its heat and bringit again -to a temperature of say 200o F. From the heater the acid enters the pickling chamber through the orifice 56, and it there is diluted tolSO working strength by mingling with the water 4coming from the rinse chamber over barrier.

A few incidental matters require furtherv mention. First, the matter of temperature. The pickling/operation is conducted at relatively high temperature, aboutY 200" F. The spent pickling solution is'hot and it enters the reclaimlngzapparatus at a temperature not far below 200. There, as is 90 explained in our copending case already alluded to, a portion only (and that a relatively small portion) of the heat is lost, for, by suitable heat transference, the liquid, first chilled to remove the copperas, is, before it passes on, heated again. In the heater the minimum loss necessarily incident to reclaiming is restored, and the reclaimed and strengthened solution renters the pickling chamber at the temperature of pickling. it has been noted in the progress of the specification that the sheets areheated in preparation, for pickling, and that the rinse water, which in the pickling chamber becomes the diluent for the acid, is supplied at a temperature near the boiling point.

The rate of flow of rinse water and the 'rate at which'fresh acid is supplied will be \commonly conducted hy rogen recovery is practically impossible. In the practice of our invention it becomes wholly practical, and indeed ve simple. By virtue o the spray system now described, acting uponv the continuously Aad- .vancing succession of sheets, it will be observed that each sheet in turn passes beneath a succession of sprays and that while these sprays are 'of different degrees of purity and intensity so farA as concerns acid content, there is one spray, preferably the last in the succession which the sheet en-A @was in aaah che' .sprayed- Qn sont@ 1s is practically free of cepperas. We preferably, in the performance of the operation, so

article -to a continually fresh stream; (5)

the high temperature due to preheating of the sheets and-preheating of the solution; (6) the washing away of adhering bubbles of' hydrogen--is tomake possible continuous pickling as it has not to our knowledge bee possible heretofore.

A. limitation which has heretofore been deemed insuperable in pickling has been that high temperature is impracticable, be? cause, when sheets are taken from the solution which is too hot, they emerge coated with an objectionable black deposit. The black coatin is ormed after the scale is removed an while the sheets remain still in the pickling bath. By removing the sheets from thejaction of the pickling solution immediately on the disappearance of the scale (the time of operation ma be regulated by controlling the speed o the conveyer, to meet any condition), and by carrying the sheets immediately, as soon as pickling is completed, directly Jfrom acid sprays to water sprays, and then bringing them progressively into 'a' drying chamber, the development of such a' black deposit is prevented.

We have in the foregoing specification described in some detail a number of pieces of associated apparatus, and the mode of operating them. Much of this showing is exemplary, and our invention is by no means confined to an exact followi of such in-` struction. In the ensuing claims we define the essence of our invention, and. so long as this be present, our invention will be practised, regardless lof whether the minute 'description given be adhered to or not.

We claim as our invention:

1. In apparatus for pickling sheet metal means for projecting laterally a succession of sprays of pickling solution, and means for sustaininga sheet of metal in vertical position and for causing it to advance through such succession of sprays, substan tially as described.

'2. In apparatus forpickling sheet metal in continuous operation, means for sustaining `a succession of sheets invertical position and for causing them to advance while so sustained and means for projecting upon j opposite surfaces of each sheet as it advances sprays of ickling solution, substantially as describe f 3. In apparatus for removing scale from the surface of a iiexible metal article, the combination ofmeans for bending the article and thereby loosening the scale upon it, means for maintaining a spray of pickling solution, and means for feeding the article from the bending means through the spray of pickling solution, substantially as described.

4f. vIn apparatus for removing scale from the surface of sheet metal, the combination of a bending apparatus consisting of a plurality of rolls between which the sheets are passed, means for heating the rolls of said ending apparatus, meansv for maintaining a spray of pickling solution adjacent such bending apparatus, and means for causing the sheets delivered from said bending apparatus to advance under such spray of pickling solution, substantially as described. 5. In pickling apparatus the combination of a trough subdivided by barriers int/J compartments, with communication over said 'form of spray above the trough, and means for causing an article to be pickled to adi vance above the trough and through the succession of sprays defined, substantially as described. Y

6. In pickling ap aratus, the combination of a trough subdivid) partments, with communication over said arriers from compartment'to compartment, means for causing a stream of water entering at one end to flow through said trough t the other end, means for introducing into a compartment other, than the rst a stream of pickling acid, means for withdrawing from each compartment portions of the liquid therein'contained and projecting them in the form of spray above said trough,

means for causing an article to be treated to advance above said trough; through such sprays, and in a direction opposite to that 1n which the liquid flows through the trough, substantially as described.

7. In'pickling apparatus, the combination of means for lmaintaining a flowing stream lof pickling solution, means for withdrawing from the stream at successive ints portions of the flowing liquid and or projecting in a succession'of s rays the portions withdrawn, and means or causing an article to be treated to tra'verse said sprays in a direction countercurrent to the stream, .substantiall as described.

ed by barriers into comv 4 of a closed chamber, means for causing the tion an y to advance in closed cycle, in a path which t shall in art intercept the path for the ararticle t'o be treated to advance through said chamber, means for directing upon the article advancing within the chamber a spray of pickling solution, andmeans for removing the as generated by the pickling operacollecting in said chamber, Substantially as described.

9. In pickling apparatus the combination of means for causing. a succession of arti-v cles to be treated to advance in a determined path, means for causing pickling solution ticles to e treated, means for causing the `solution to form a spray in that part of its path which coincides with the vpath of the material, and means `for subjecting the pickling solution elsewhere in its cycle to a reclalming operation, substantially as described. v

10. In pickling apparatus means for projecting a flowing stream of pickling solution in a succession of sprays and means forcausing the article under treatment to advance through the sprays in a direction counter- -current to the stream, substantially as described.

n testimony whereofl we have hereunto set our hands.

' HENRY S. MARSH. RALF Sv. COCHRAN. Witnesses:

Mrs. C. G. SHFFER, En. J. Russnnfr. 

